The present application relates to a plate-type heat transport device for transporting heat by a working fluid driving force produced due to a capillary force using latent heat due to the phase change of the working fluid, and a display having the transport device mounted thereon.
Among heat transport devices using latent heat due to the phase change of the working fluid, a thin heat transport device has been known, which is constructed of a plurality of substrates bonded to each other with grooves for allowing the working fluid to pass therethrough (see Japanese Unexamined Patent Application Publication No. 2004-108760, [0038], FIG. 1, and Japanese Unexamined Patent Application Publication No. 2004-190985, [0020], FIG. 1). In the heat transport device disclosed in Japanese Unexamined Patent Application Publication No. 2004-190985, an evaporator and a condenser of the working fluid as well as a gas path and a fluid path, which allow the evaporator and the condenser to communicate with each other, are formed on the substrates. Also, on each of the substrates, the micro groove is formed for generating a capillary force as a pumping force of the working fluid.
Recently, thin-type television sets using FADS (flat panel displays) have been available, and heat generated from their display panels poses a problem. In a liquid crystal display, for example, if an LED (light emitting diode) back light is used, a large quantity of heat is generated from the entire surface of the display panel. Display panels using a plasma display and an OLED (organic LED) also generate heat in large quantity.
Then, the entire surface of the display panel may be covered with a solid metallic heat-radiating plate. However, since the thermal diffusion of a general heat radiating plate depends on the thermal conductivity of a metal, its responsiveness is a problem. Also, since such a heat radiating plate requires its own rigidity, it disadvantageously has to have a thickness and a weight to some extent. When the display panel becomes larger in size, the panel is difficult to be uniformly cooled so as to generate temperature unevenness on the panel, resulting in unevenness in brightness and color of display images.
On the other hand, when a display panel is cooled using the heat transport device mentioned above, a problem also arises. For example, even if the evaporator of the heat transport device disclosed in Japanese Unexamined Patent Application Publication No. 2004-190985 is attached to a display panel, it is difficult to uniformly cool the display panel over its entire surface. Even when the heat transport device is used, if a heat source is located on the surface of the display panel, especially in its upper portion, the working fluid may not be supplied to the heat source by only the capillary force because of the gravity force applied to the working fluid. This case cannot also anticipate so much the uniform cooling.